Here is a link to the Everyday Math site. It has many words that we use and some that we don't. They are in ABC order so you can easily find what you are looking for.Math Vocabulary Definitions
Number Concepts VocabularyMath Word
Definition
 digit
A symbol used to make a number.
numeral
A symbol used to represent a number.
whole number
The numbers 0,1,2,3,4,5,6,7,8,9,..............
place value
Is the value given to a digit by its place in a number.
Example: In the number 5,349 the 3 is in the hundreds place and
has a value of 300.
period
The three digits that make up the places between two
commas in a large number.
Example: In the number 123,456,
123 is the thousands period and 456 is the ones period.
standard form 
The usual way of writing a number that shows only its digits,
no words.
pattern
A sequence of numbers, figures, or symbols that follows a rule
or design.
round
To change the value of a number to one that is easier to work with.
is equal to (=)
 Having the same value.
(>) 
is greater than
(<)
is less than
multiplication
Multiplication is one of the four basic operations. It can be thought of as repeated addition:
4x3 can be interpreted to mean 4 3's or 3 + 3 + 3 + 3 = 12.
factor
A factor is a number multiplied by another number to find a product.
product
A product is the result of multiplication.
array
An array isa set of items arranged in rows and columns.
division
Division is one of the four basic operations of arithmetic where in the division statement a ÷ b = c, a is the dividend, b the divisor, and c is the quotient.
area
Area is the number of square units that cover a figure.
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